Adhesive composition



Patented Oct. 28, 1 930 UNITED STATES PATENT O E WILLIS A. GIBBONS, OFLITTLE NECK, NEW YORK, ASSIGNOR TO GENERAL RUBBER COMPANY, OF NEW YORK,N. Y., A GORPORATION OF NEW JERSEY ADHESIVE COMPOSITION No Drawing.

for preparing artificial latices o'r dispersions of rubber in water. Butthese artificial la-,

tices do not possess the same adhesive proper ties as the naturallatices, particularly in regard to leather, for they do not penetratethe leather.

. The present invention has for its object an improved process forbonding the surfaces of materials together. Still another object of theinvention is to unite leather articles with 1 a leather cementcontaining an aqueous dispersion of rubber and at the same time utilizenif'aterial whichshall have the property of faci-litating penetration ofthe cement into the leather. With a particular embodiment in mind, butwithout intention to limitthe scope of the invention beyond what may berequired by the prior art, the invention consists in treating leathersurfaces with a cement composed, at least in part, of an aqueousdispersion of rubber, treating the surfaces also with a material adaptedto increase the penetration of the rubber dispersion into the surfacesto be joined, and in joining said treated surfaces. More specifically,the invention consists in treating leather surfaces with an aqueousdispersion of rubber, treating the surfaces also with a base adapted toincrease the penetration of the rubber dispersion into the surfaces tobe joined, and in joining said treated surfaces.

As a specific example of the preferred method of applying the invention,an aqueous dispersion of rubber is prepared by any suitable means, andto this dispersion is added aquantity of a base such as ammonia. Thebase may be added as an aqueous solution, or the Application filed March6, 1925. Serial No. 13,663.

dispersion may be caused to absorb a sufficient quantity of, gaseousammonia. The amount of base may be varied, but 2%, calculated upon thetotal volume of the dispersion, will be found to give satisfactoryresults. Other bases may be employed, such as trisodium phosphate, orthe caustic alkalies, or other alkalinematerials which have the propertyof increasing the penetration of the rubber dispersion into the surfacesto be joined. The leather surfaces are then coated with this mixture ofcement and base, and joined. When. the cement has become dry, the twosurfaceswill be found tightly joined. If no base has been added with thecement, the two coatedsurfaces do not adhere well, but can be separatedwith comparative ease, and frequently the separation is such that a searateand distinct film of rubber can be strlpped from the surfaces. Thisindicates that the dispersion has not penetrated the leather surfaces,but has remained entirely upon the surfaces. When a base, such asammonia is in contact with the surfaces at the same time as thedispersion, the latter penetrates the leather and givesa high degree ofadhesion between the surfaces.

This increased adhesion may be due to-the swelling action of bases onthe leather, rendering the leather more absorbent. Other bases may beemployed, and the same principle may be applied to other materials thanleather, where such materials show anincrease in absorbing power whentreated with swelling agents of the nature described.

Examples of the cement are as follows, I

although other proportions and other ingredients than those given may"be used. Vulcanizing agents and combinations may also be incorporated. a

p E wample #1 30 partsby weight of rubber,

10 parts by weight of silurian shale,

1.58 parts by weight of water. i i

' Example #2 20 parts by weight of rubber,

8 parts by weight of silurian shale,

70 parts by weight of water.

act as a preservative.

Two par-ts by weight of a base such as ammonia or trisodium phosphatewhen applied to'surfaces such as leather at the same time as either ofthe above cements will render the surfaces more receptive of the cement.

The invention does not contemplate the use of ammonia with naturalrubber latex, in a way that would allow the ammonia to per form itswell-known function of preserving the latex against coagulation Nor arethe appended claims to be construed as reciting the addition of ammoniato natural latex under conditions in which the ammonia could However,the addi tion of ammonia to natural latex which already contains a fulland sufficient quantity of a preservative other than ammonia and wherethe'ammonia has neither opportunity nor need to act as aupreservativedoes lie within the scope of the present invention.-

Having thus described my invention, what I claim and desire toprotect'by Letters Patent is:

1. A process. for bonding the surfaces of materials together whichcomprises treating said surfaces with artificial aqueous dispersions ofrubber and with a material adapted to facilitate the penetration of saidrubber dispersion into said surfaces, and joining said surfaces.

' 2. A process for cementing leather surfaces together which comprisestreating said surfaces with artificial aqueous dispersions of rubber andwith a' base adapted to facilitate the penetration of said dispersioninto said surfaces, and joining said surfaces.

3. A process for cementing leather suro faces together which comprisestreatingsaid surfaces with artificial aqueous dispersions of rubber andwith an agent adapted to swell the surfaces and render them moreabsorptive, and joining the surfaces.

4. A process for cementing leather sur faces together which comprisessimultaneously treating said surfaces with artificial aqueousdispersions of rubber and with ammonia, and joining said treatedsurfaces.

- Signed at New York, county and State of New York, this 28th day ofFebruary, 1925;

WILLIS A. GIBBONS.

